The well-known research carried out by Busenitz and Barney (1997) exploring differences in the decision-making processes between entrepreneurs and managers in large organizations has been revisited and redesigned as a starting point to create a computational and theoretical Multi Agent Model (MAM) which shows differences in the decision-making processes. In the original study, researchers showed the presence of a different disposition in incurring in biases and in heuristics by entrepreneurs and managers. In particular, two interesting trend curves on the Overconfidence effect have been realized. Authors concluded by stating that the Overconfidence effect is significantly different in entrepreneurs and managers and helps distinguish between these two work categories. Starting from this conclusion and from their results, a computational and theoretical MAM has been designed, where, as suggested by the authors, different decision-maker agents can incur in the Overconfidence effect with different degrees.